Step 1

Heat the oil in a deep pan or flameproof casserole dish over a medium-low heat. Stir in the onion with a pinch of salt and cook for 10-12 mins until softened. Tip in the garlic and peppers and cook for 5 mins. Mix in the coriander stalks, spices, oregano, sugar and chipotle paste if using. Cook for a further 5 mins, until everything is well combined and softened. Pour in the beans, along with their liquid, the tomatoes and stock. Season well and bring to a simmer.

Step 2

Leave to simmer on a low heat for 1 hr-1 hr 10 mins until thickened and reduced. Stir in the dark chocolate and season to taste. Serve over rice with lime wedges, avocado, soured cream and coriander on top.